Production of anthraquinone-azines



Patented Jan. 27,1931 7 UNITED STATES PAUL NAWIASKY AND LUDWIGEIFFLAENDER, E:LUDWIGSHAFElN-QN-THE-RHINE, GERMANY, AssIGNoRs'ro GENERALANILINE.WORIS,INQ., QENEW@YOBK, N. Y., A

, CORPORATION OF DELAWARE PRODUCTION or nnrnnnonrnonnmz rivnsg if 1 i NoDrawing. Application filed October 27, 1927, ser aijiq ffaasas; arm inGerman emb "811926. I

The present invention relates to improvements in the production ofN-dihydro- 1.2.1.2-anthraquinone-azines.

It is known that the valuable blue dyestufi 5 N-dihydro-1.2.1.2'-anthraquinone-azine can be obtained by the action offused caustic alkali on 2-aminoanthraquinone, with or without theaddition of oxidizing agents,- the melt being poured into water andoxidized with air. In order to improve the yield, it has also beenproposed to add to the melt salts of low fatty acids, such for exampleaspota ssium formate, potassium acetate, and the like,

in'the presence, if required, of an inert diluent, or to add alcoholatesor phenolates, such as sodium butylate, sodium phenolate, and

the like.

We have now found that still better yields 7 f th id dyestuff or of itsderivatives wh starting from substituted' 2-amino-anthraquinone, may beobtained if salts of low fatty acids, namely of formic, acetic orpropionic acid are added to the caustic alkali melt in conjunction withorganic compounds containing at least 3 carbon atoms in their moleculeand also containing a metal attached to an oxygen atom. As examples ofsuch organic compounds may be mentioned salts.

of fatty acids with at least 4 carbon atoms, in particular soaps,further metal alcoholates or phenolates. For example, sodium acetate maybe added'in conjunction with 7 5 arts of dehydrated sodium acetate areintro uced into a melt of 2000 parts of caustiopotash-s o'da 'atatemperatureof 250C 7 parts of sodium""glycerate 3 being then} added;andthemi'xture stirred untilunifor-m distribntionfhas taken place. The'mixtureis next cooleddownto a temperature of 210 (1. and :500. parts;of fi-aminoanthraquinone are introduced in such a way that the temper-'aturei-doesnot rise ab0ve'230 C; The wholemixture is maintained at atemperature of 225 C. until no further'increase in the pro thraquinonecan no longer be-detected. The

meltis then treated in the usual manner.

Examp 2 15. parts of dehydrated sodium acetateare stirred into 200 partsof a mixture, in molecular proportions, of caustic potash and soda at atemperature of about 200 (1., 20 parts of soap being then added.Thereupon parts of ,B-aniinoanthraquinone are introduced, and themixture is stirred at a temperature a of from 200 to 210 C. until theproduction tained by evaporating 'su 'te cellulose waste liquor, saltsof diisopropylnaphthalene sulfonic acid or bile acid, Turkey-red oil,acids tar, and the like.

Example 3 C. and 500 parts of ,8-aminoanthraquinone are introduced insuch a way that the temperature does not rise above 230 C. The wholemixture is maintained at a temperature of 225 C. until the production of'dyestulf ceases to increase and B-aminoanthraquinone can no longer bedetected. The melt is then treated in the usual way.

obtained by the sulfonation of brown-coal What We claim is: 1; Theprocess of producing N-dihydro- 1.2.12' anthraquinone azine whichcomtion With an alkali metafcompoim'dbfafi al coholxcontainingatleastthigee carboniatomsa 31 The process of producing N-dihydi'oprisessubjecting Q-amino-anthraquinohe to the action of a, causticpotash-sodamelt in the presence ofsodilimaacetateain conjunction with analkali metal butyrate.

2. The process of producing N-Hili'j'rdi'b-1.211";2?.-anthraquinone-azinesu which prises subjecting a2-amino+anthnaquinonetoia the action of a caustic alkali melt in thepresence of a salt of a 10w fatty ,acidin COI DjI IILC:

1.21.2fanthraquinone-azines which; comeprisessubjecting;a12gamino+anthraquinone t'm the) action; 015a caustic;potashesoda; melttin: the: PIQSQIICQLOTE a: salt of :txlowfattyacidg'i'm conjunction WlthiaD alkali metal compoundi of: 3111311001101coiitainingatleast three carbon Intestlinonywhereofwwe:havehereuntozset;

our "hands;

PAUL NAWIASKY. a a EIFELAENDERa,

